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Old 01-23-2018, 12:02 AM   #1
Scooby Newbie
Member#: 445894
Join Date: Apr 2016
Chapter/Region: NWIC
Location: Washington
2017 WRX

Default MapDCCD and Advanced Wheel Speed Sensor Installation Guide 2015+ WRX

MapDCCD and Advanced Wheel Speed Sensor Installation 2015+ WRX

This is not an easy install for the average gear head. It involves a lot of electrical work and tapping critical signal wires. I've done what I can to simplify that part for you, but heed the warning, if improperly done you can have issues ranging from a fire, to losing a wheel speed sensor, or the TPS signal! The ECU will hopefully go into limp mode, there is a secondary TPS signal after all. Perform this at your own risk, or hire a professional, I've done the hard work for them.

I have only confirmed the pin mappings / wire colors on the 2017 WRX USDM. 2015/2016/2018 should be the same but I do not have those service manuals to confirm. I'm sure others can help here.

If you just want the pin mappings/etc skip to the spreadsheet. The rest of this is just a little verbose. Note the sheet has tabs for the pinouts and pin locations.

DCCD: Driver Controlled Center Differential
DCCDC: Driver Controlled Center Differential Controller (the MapDCCD)
AWSS: Advanced Wheel Speed Signal Processor (MapDCCD Advanced Wheel Speed Signal Processor)
TPS: Throttle Position Sensor
RPM: Rotations Per Minute
ECU: Engine Control Unit
VDCS: Subaru's name for the wheel speed computer / abs control unit
DMM: Digital Multimeter
VSS: Vehicle Speed Sensor/Signal

Why MapDCCD:
I chose the MapDCCD with the AWSS for itís tunability. It also accepts a variety of inputs and lets you choose which signal to use to calculate lock percentage. Even if you are not interested in doing this yourself, it comes with a large set of base maps that cover most scenarios. I would consider the AWSS for advanced situations, or those that want the best. You certainly donít need it, and can see a large benefit with just the MapDCCD. Itís for those who are chasing the last tenths of a second, or just needs to have the best.

Identifying which way to proceed:
There are many ways to do this install, ranging from the ultra-minimal manual only mode, to tying in the wheel speed processor for an actual slip calculation. The manual covers the different signals required for different modes, and several optional taps. The only one I can't identify on this car is the ABS activation signal, there is no wire/pin like there use to be, and it's not labeled on the diagnostic pinouts. It's use is limited anyways.

This guide covers up to the wheel speed processor and all but the ABS input. I recommend this way of course, but I am a tinkerer. Being able to write my own maps based on the sensor of my choosing, especially a measured slip output, is great.

The typical install would just be the MapDCCD with RPM and TPS. However, the brake and handbrake signals are trivial compared to the rest, and should be worth doing. It is up to you to decide what is right for you. Auto may be enough if you just want to romp around in the snow or dirt occasionally. Really the DCCD controller is not needed in the wet or dry at street speeds,motorsports being another story.

Using the AWSS gives you an excellent VSS signal to drive the MapDCCD as well as a signal representing wheel slip front to rear, which in my opinion, is the main selling point. The AWSS manual goes over how this signal is formed.

Required tools:
Cheap crimper
Wire cutter
Sharp knife
10mm socket
10mm wrench
14mm socket
#2 Phillips screwdriver
Various flat blade screwdrivers
Needle-nose pliers
Heat gun
Light (your phone LED just won't cut it)
Computer with Windows and USB, most will work

Optional tools:
Wire stripper (I typically use my side-cutters or a knife)
Drill and 3/8"-9/16Ē bit (to hide DCCD unit wires depending on mounting location)
Ratchet crimper with dies for respective crimps
Various other crimp tools as needed
12mm socket if removing intercooler
Fish tape of some kind
Pin tool (removing pins in case of mistakes, etc)

Required parts:
Waterproof butt splices
High quality wire 20/22ga (signal)
High quality wire 18/16ga (power/ground/pwm)
High quality electrical tape (I prefer 3M Super 33+)
Zip ties

Optional parts:
2 pair 4 conductor twisted pair shielded wire for AWSS
Waterproof connectors
Aftermarket firewall grommet or two
ECU pin for RPM signal (non-push-to-start only)

Controller placement:
The MapDCCD has an accelerometer and, if being used, should be positioned in the center of the vehicle. It should be mounted firmly and not wiggle around. Read the manual for more information on orientations and placement location. Typical locations are at least along the vehicle centerline and include the dashboard, the tray under the radio, an empty radio bay, or in the center console.

I've chosen to place the MapDCCD in the center console, as it's about as good of a center as you can get, is hidden away from thieving eyes, and looks stock until you open the console.


I mocked the MapDCCD up in the tray under the radio. I wasn't happy with how it fit or how it was visible. Note you need to mock this up with the wiring harness on the controller, and make sure a USB cable will plug in while it's mounted.

The AWSS can be anywhere it will fit.

Notes on wiring:
DISCONNECT THE BATTERY. I really shouldn't have to warn you about it if you are attempting this, but here it is anyways.

You need a 12v ignition switched power source. I recommend a 10 amp fused circuit with a relay for the ignition switch. I used the telematics circuit, since I removed it. It has a 7.5amp fuse and 20ga wire. 20GA WIRE YOU SAY? Yes, and the OEM rated it for a 7.5amp fuse, it's a fairly short run so the voltage drop is low. If you are really that worried, run a fused wire from the battery or some other higher current source. You can use the same telematics ignition tap (since it's just driving a relay) or find another source if you don't have telematics, there are many. You donít want to use ACC, only Ignition.

The relay I had on hand is rated for 40amp, so it's a little big...

You can also use the ground from the telematics, or find your own chassis based ground. Ideally the ground is close to the MapDCCD. This cannot also be used for the signal ground, unless you are only running manual mode, where there is no ECU connection.

All of the signal taps you have to make are in the engine bay. Both the ECU and the VDCS are there. Since you are taping critical signal wires for engine function you cannot mess these up. While you may survive without waterproof splices, I don't see why it would be worth taking the chance of getting stranded. There are many ways to do this, most will work. I highly recommend something involving heat shrink with glue in it. The glue will secure the wire to the heat shrink and form a waterproof seal. I'm going to cover 3 ways of doing this. I just hope the comments don't turn into a war here... This is my preference from my experiences.

Waterproof butt splice connectors: This is what I've chosen as a test. The connectors I used have a mismatched crimp end to end, which allows you to change wire gauge, or add another wire. They are Hydralink Heat Shrink Multiple Wire Butt Connectors. They are not cheap, but they work well. This method involves cutting the factory wire, splicing both ends, twisting your tap wire onto one of them, and crimping them back together. Then you melt the heat shrink from the crimp, outwards, and the glue seals everything up.

Uninsulated butt splice connectors: The same as the above except you have to use your own heat shrink. The drawback vs the insulated connector is that on some taps you won't have much room at all to slide the heatshrink on. It's however much easier to find the components, and cheaper.

Melt, wrap, and solder: This is a no-cut method, but has its drawbacks. It's hard to melt the jacket on these wires cleanly. Once you have a section of bare wire you wrap the tap wire around it, and solder the joint. This does not allow the use of heat shrink, you must use some form of tape only... It also leaves you with a brittle solder joint and no glued heat shrink to support it.

The factory harness has many splices in it already, in fact we are going to use the factory splice locations on the ECU harnesses. They were chosen as a low flex spot and are already stiff from the other splices.

A lot of the taps here (9) are on grounded shielded wire bundles. Your only option is to tap them on either end or cut the shield, make your splices, and rebuild the shield. Leaving the shield cut will defeat much of the purpose of a grounded shield.

You can make all of these taps in a permanent way, with no connector between the MapDCCD/AWSS and signal taps, but you will still need your own wire and an additional set of butt splices. The ECU is no longer in the cabin so the harness wires are not long enough. The advantages of this method includes cost, simplicity, and signal quality. The more connections you add the better your chances of a bad connection.

You can also go to the extreme, and use waterproof connectors like I have to allow you to make disconnects at key locations. I used MetriPack 150 series connectors as I've worked with them before and they work well. You can use whatever you like here. A 10amp rated connector is more than enough for the DCCD drive, so you can use the same connector for this and signals.

Measure wire runs in car, and build as many pieces of the harness you can outside of the car. This includes wrapping the wires into a harness. Your choice of wire wrap may vary, I use electrical tape.

The pins I found are part compatible even though they are not identical in design. The important dimensions all are the same. I cannot find the identical pin, but it does not matter. It took a lot of work to figure out what connector this was. It's a CMX receptacle with CTX64 pins.. These are Molex CTX64 Receptacle Terminals for 20ga wire #0348033212. They also sell them for 22ga.

Having researched this, there is no matching male plug, and not even an over the shelf header for all 3 receptacles, so making a patch harness that just plugs in is not really feasible. Subaru sells a test one that gives you measurement points, but wants a lot of money for it, and itís not waterproof anyways...

Running the interior wiring:
I placed the disconnects, relay, and main junction location between the back of the radio and the glove box. You can easily route from the firewall hole down to here, to the radio for handbrake signal, pedals for brake signal, etc. I may also place the AWSS here. There is a good amount of room, but keep your wires off the backs of the airbox motors. A bonus of this location is if you make everything a little long, it hangs down into the footwell for making connections, crimping connectors, splices etc. Just zip tie it up after.


Since the MapDCCD is in the center console, I ran the wire out the forward side of the console, along the transmission tunnel, and left the ends hanging in the passenger footwell to terminate. All this requires is removing the center console and the shift boot. To remove the center console remove the two bolts in the bottom of the compartment (under the felt) and screw under the handbrake boot, which comes straight up, then pull up for the last tab. To remove the shift boot place your fingers under the inner edge and pull up. Its easiest to drill the wire hole into the console from the underside of the center console.


Interior taps:
The dimmer signal, brake signal, and handbrake signal are done inside the cabin because there is no need to do them outside.
Choose your source for power, ignition, and ground. In the notes above I explained my source. Splice them into the harness or make it pretty with a connector.


The dimmer signal is available at the radio, as well as the handbrake. The brake is not, but it is right at the brake switch under the steering column. You should be able to easily get from the footwell to the radio pocket, then to the drivers footwell with the wire.

If you have a factory radio you have to remove quite a bit to get the radio pocket. There is already instructions for this online. You might as well throw it out while it's removed. If you have an aftermarket, you've done this before already, but you only need to remove the trim and HVAC controls, giving you enough room usually.

Getting from the interior to the engine bay:
There are many ways through the firewall. I like to use the two grommet filled holes which, on the STI, would have the sound generator tube in them. The first is right near the top of the firewall on the passenger side. The other is inside of the cowl. These holes provide an easy and clear route down to the footwell. Aftermarket grommets fit both holes. You can slice them yourself if you want but you lose the zip tie hold/seal. In my case the AOS lines cover the grommet, as shown. You may have to move the AOS out of the way later on, anyways, to pull the ECU wiring out enough.


You must remove the cowl cover. Anyone who has done this before will groan here. Lift the wipers off the windshield. Pull the nut covers straight up off the wipers then use a 14mm socket to unbolt the wipers and remove. Don't try to flatten them. Push the pin in each clip then remove the clip from both side cowl covers. Unclip them from the main cowl cover by pulling the base up. You donít need to remove them. Don't get them stuck on the hood. Make sure the side cowl covers are below the hood before lifting the hood up.


Remove the clips holding the cowl cover to the firewall. The side ones are Phillips head, twist, then lift out. The center 4 will make you hate Subaru. The manual says to squeeze in a specific part and lift, but it's a pain. Plan on breaking them and replacing them if you want the quick way. If you are good with slotted drivers you can also insert them into the slits in the white half, and twist to allow the pin to be lifted. This takes 3 hands or a lot of practice.

The cowl will now pull forward and unclip. You have to unclip the entire cowl, but do not pull the driver side off much. The washer hose is still attached. It will sit almost in place on the driverís side and rest on the engine/cover on the passenger side. This gives plenty of room to work.


Pull the firewall grommet, and cut or replace. Pull the interior grommet. You can now see the insulation behind it.


Pull the insulation out through the hole using needle-nose pliers or other tool. It is held in by two tear out tabs so it just needs a tug. You could leave it and force the wires through a gap as an alternative. Drop the fish down the hole and see it in the passenger footwell near the kick cover. I prefer a heavy, flexible piece of wire for this, a high strand count 4ga worked.

If by now in the process, you still want to pull the cowl cover ever again, you may want to consider replacing windshields as a career. Do yourself a favor and don't just pull all the wires you need, for signal taps and dccd feed, also pull at least one spare thicker gauge wire through. This wire can be used to pull wire later on, if something needs to be changed or added. There are numerous points to tie them off to prevent them from falling out.


Once your wires are through both grommets, and not just both holes, you can put the cowl cover back on, in reverse order. Wipers should align with where they came off, heated wiper rests makes this easy, or just the usual dirt line.
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Old 01-23-2018, 12:02 AM   #2
Scooby Newbie
Member#: 445894
Join Date: Apr 2016
Chapter/Region: NWIC
Location: Washington
2017 WRX


Tapping the ECU:
Now that you have wires into the engine bay it's time to prepare for some taps and / or connectors. Put a connector onto the dccd drive leads or splice it into the harness. Follow the other harnesses on the firewall and zip tie yours to it, to keep it from moving too far.


If you don't have an AOS that mounts where my IAG does, you most likely have several harness clips on brackets that will need to come off. They are on the bundles feeding the ECU. Pinch the back of the clips on the tabs and push them out. If the steering control unit is in the way, unbolt it and the bracket. You want a lot of room to work in this area, you need to get your crimper in there. Remove the ECU by unbolting the two bolts on it and pull up to remove it from the bottom two holes. You can push the ECU to the firewall a little bit to squeeze it out, but your charge pipe may be in the way and need to be removed. Now that the ECU is out you can disconnect it. Starting on the smallest connector, push the lock tab in and swing the lever until it clicks in the other direction. Finish removing the plug and repeat with the two larger connectors.

Now that the ECU is out of the way you can maneuver the lower harness bundles up and out a little bit. Be careful not to pull too hard on the harness, and make sure it does not get snagged. You will barely get enough room to work on the lower one. The upper one goes over the charge pipe and is easier to work on.


Remove tape from the first 6-8" of each harness and peel back the vinyl covers. You will see many splices in this location, mostly ground. This is a good location for your splices, as it's already pretty firm. Run your three wires along the factory harness to get the wires up to the tap location.

Two taps will occur on the brown ended connector (the lower harness) if you have push to start. These are RPM and Signal Ground. Cut one of them, and strip each end to the proper length for the splice. Crimp the harness side, then twist your matching signal wire to the ECU side and crimp it as well. Check your crimps for a solid connection by pulling out on them. Strength varies, If it comes out too easily it's not a good crimp. Locate the other splice in a slightly different location to not cause a large bump. Don't heat shrink yet, as you want to make sure your signals are good first.


If you do not have push to start, the signal ground tap is the same. The RPM signal wire doesn't exist, so you have to put a pin on your signal wire. Cut it to an appropriate length. Now you have to disassemble the connector. Unlock the locking lever and position it so the pivot pin tabs are aligned with the holes in the lever. Pull each side off slightly then remove lever. Look at the wire cover on the back of the connector. Carefully cut the zip tie, I prefer old side-cutters. On the other side of the cover, there are two locking tabs and you can slip a small flat blade in on each one. Now slide the cover off the connector towards the tabs.


Identify the RPM pin hole and remove the white plug from it, with needle-nose pliers or a pick. Remove the brown pin cover. There are numerous tabs around it that need to be released. Do not break the locking tabs on the narrow sides. Push your signal wire through the RPM pin hole until it comes out the pin side of the connector. Strip and crimp the wire, align it like the others, and set it in the hole. Note the orientation with the hole in the pin facing the plastic retainer tab. Slide the cover back on and secure to wires with a zip tie like the one you removed. Place the lever back on and return it to the locked open position.


Realize now that you hate this molex design and move on...

The TPS tap is on the black connector (upper larger harness). This will be a trickier tap than the other(s), the wires from the TPS are shielded. Using the information above choose your method, and tap the TPS wire. Note there are TWO blue wires on this connector, and both have the same color wires in their bundle. One is the TPS, one is the pedal. Make sure you have the right wire. This is a very tight tap if you take the easy way and you won't have space to make a second attempt. To get my splice to fit, I had to trim the heatshrink a little on each end and remove some of the factory tape until you see the shield. Make this splice as far away from the connector as you can, with your heat shrink butting right on the bare shield.


At this point you have enough to test these signals and the MapDCCD. Carefully hook the ECU up, but leave it out on top for an easier time. You have to put the smallest connector on first, then middle. Make sure everything inside is good, and no wires are hanging on the belt. Hook the battery back up and turn key to on. Verify MapDCCD initializes and connect to it. Go to setup and step on the throttle, you should see the Throttle % readout increase. You don't have to tune the input yet, for now you can just make sure it will hold with the pedal position. Note most pedal maps are not 1-1 and if you are not smooth it should jump then return to normal. You could start the car and check with some more noise if you want, but remember the ECU is dangling around in the bay.
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Old 01-23-2018, 12:03 AM   #3
Scooby Newbie
Member#: 445894
Join Date: Apr 2016
Chapter/Region: NWIC
Location: Washington
2017 WRX


Pull the battery lead again, and the ECU again. Heat shrink your splices. I use a rag or thicker paper towel to separate my splices from the harness, so you won't melt anything you don't intend to. Wrap up the grounded shield you uncovered, and if you want wrap your splices, it will now look as good as OEM. Pick an opportune place for your wires/harness to exit. I used the ECU end as it was easiest. Wrap the harness back up in the vinyl and then tape it back up. You may have noted the TPS tap is on the top of engine harness and it should be removed independently, but you just ran a wire to it. You can put a connector here to allow disconnection, or just some extra wire for play. Wrap your tap harness up and zip tie or wrap to main harnesses as needed. Put the ECU back in and anything else you removed.


At this point you are done with all of the ECU taps in the engine bay. If you want, you can get the VSS signal from the VDCS. If you are installing the AWSS you don't need that tap, just 9 others... It's optional to add functionality to the MapDCCD as well. More info on routing for this is under the next section.

Tapping the VDCS:

[This section to be added upon completion]

Wiring the AWSS to the MapDCCD:
Wire AWSS VSS output into the MapDCCD VSS input, and do the same with the slip output, into the MapDCCD 4d input.

Finally, tie your wiring up safe under the dashboard. You don't want someone's foot to come into contact with it. Put anything still apart back together and clean up the seemingly endless sprawl of wire insulation pieces. At this point you are done and can move onto calibration of sensors and writing maps.

RPM: 2 pulses per revolution
TPS: Usually 0.7~v-3.9~v


Thanks for reading, I hope this helps with this install.

Copyright 2018
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Old 01-23-2018, 03:19 PM   #4
Scooby Specialist
Member#: 424203
Join Date: Jun 2015
Chapter/Region: NWIC
Location: Mountains WA
2016 WRX stg 4 Rally
STI Drivetrain GM


YOU ROCK!! thank you!!
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Old 07-24-2018, 07:10 PM   #5
Scooby Specialist
Member#: 408776
Join Date: Dec 2014
Chapter/Region: BAIC
15 WRX EFR 7064


Why did I not find this earlier? I've done hours and hours of hard work just like yourself to map everything out, ran my wires the same way you did...then now at the final stages of the install I wanted to just double check some things and came across this post.

If I ever make/find the time I can post all my pictures and any extra insight to add into this thread, some day.

Thanks pal.

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Old 07-30-2018, 11:47 PM   #6
Scooby Newbie
Member#: 445894
Join Date: Apr 2016
Chapter/Region: NWIC
Location: Washington
2017 WRX


Happy I could help a little in the end! I've still got to do the AWSS install. I've been busy with road trips, work, and other projects. The DCCD controller has about 6k miles on it now, and it's quite amazing in all conditions.
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Old 08-01-2018, 07:41 PM   #7
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Member#: 408776
Join Date: Dec 2014
Chapter/Region: BAIC
15 WRX EFR 7064


I have everything just about buttoned up now, will be making all the final connections inside of the car tonight. Engine bay stuff is all done as of last night.

I tapped all of the AWSS ABS lines by opening up the loom inside of the passenger fender. This place is a bit better than in the main engine bay IMO. Tucked away out of the main engine bay, no water/elements really get to this area. I used posi-taps.
Wish I had the posi-tites, but it'll be fine...I live in California.

I soldered the two connections to the ECU after opening the loom, but used posi-tap for the TPS right outside of the shield cause I didn't want to solder this area, not enough room to comfortably splice in.
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Old 08-07-2018, 11:35 PM   #8
Scooby Newbie
Member#: 445894
Join Date: Apr 2016
Chapter/Region: NWIC
Location: Washington
2017 WRX


Originally Posted by immortal View Post
I tapped all of the AWSS ABS lines by opening up the loom inside of the passenger fender. This place is a bit better than in the main engine bay IMO. Tucked away out of the main engine bay, no water/elements really get to this area. I used posi-taps.
Wish I had the posi-tites, but it'll be fine...I live in California.
This is where I was planning on making them. Did you have any issues with cutting the shield and tapping in the middle?
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Old 10-23-2018, 01:31 AM   #9
Scooby Newbie
Member#: 314324
Join Date: Mar 2012
Chapter/Region: International
Location: Collingwood, Victoria, Aus
MY07 Lib GTB 6MT Wag


Was the AWSS install a success?
Iím attempting to compare your awesome install to my car, an Ď07 LGT which has speed sense via abs/can and no VDC.
Iím researching where to tap the wheel speed sense without upsetting the can system.
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Old 03-26-2019, 07:53 AM   #10
Scooby Newbie
Member#: 498693
Join Date: Mar 2019
2018 WRX


hey I posted this on your other thread, Can you just wire up the OEM STI center console DCCD Controller with the iwire kit? im not looking for full control of the Trans
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Old 06-28-2020, 06:19 PM   #11
Scooby Newbie
Member#: 508100
Join Date: Nov 2019
Location: NW Arkansas
2006 WRX LT Wagon


I just installed the advanced wheel speed sensor on my 06 STi Wagon swap. Next major thing will be the MAPDCCD controller. Luckily, since my ECM is in the cabin, it's a shorter link. I plan to mount the DCCD controller in the ash tray.

I have a couple of questions:

I wired my Speed Sensor to the cigarette lighter for power. I am wondering if I can safely wire the MAPDCCD here for power as well. It is a heavy gauge wire. Thoughts?

Also, just generally, I decided to do this because I had to have a speed sensor (I put a 2012 six into a 2006 so I had no speedo afterward) and it seemed like the feedback would be awesome for traction control. However, I haven't found many people who have actually done it. I am already set on this path, but are you happy with it?

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